Providing emergency services, especially in overload conditions, is challenging since service providers have to ensure that emergency calls are established regardless of other non-emergency calls. In the public switched telephone network (PSTN), there are mechanisms to identify calls made from and to special locations which involve providing emergency services. These locations include 911 call centers, police departments, hospitals, fire stations, and various government agencies. Generally, excessive network resources are reserved to ensure completion of emergency calls, and call setup requests for requesting the establishment of a call are given processing priority when they are within the various switching nodes within the PSTN. Accordingly, the PSTN currently has the ability to properly prioritize and handle emergency calls.
With respect to packet-based communications, packet networks are increasingly being used to deploy voice-based communications using various types of voice over packet (VoP) calls. Unfortunately, the openness of packet-based architectures has presented a challenge for properly handling emergency calls. Although there are numerous packet-based devices which can filter and route calls, this is no overriding solution for ensuring emergency calls are properly processed and prioritized over non-emergency calls. Further, there is a need to ensure that emergency calls can be properly handled in overload conditions as well as ensure that the system is not abused by malicious users who improperly identify their calls as emergency calls or initiate malicious attacks, such as denial of service attacks.